Cluster models used to calculate C binding energies. (a) Epoxy, (b) two OH groups, (c) two edge groups, (d) carboxyl group, (e) line defect epoxy group and EP (C-EP) group, (f) and CP, (g) five-ring lactol group, (h) six-ring lactol group, (i) epoxy-hydroxy pair, and (j) attached structure.
(a) Graphene sheet with isolated epoxy and hydroxy groups. Dashed lines mark a unit cell. (b) A GO model with epoxy and hydroxy groups. Dashed lines indicate the cell used in our calculations. Red and green spheres represent oxygen and hydrogen atoms, respectively.
New oxidation species. (a) Epoxy pair, (b) epoxy-hydroxy pair. The corresponding carbon atoms (red) are named as C-EP and , respectively. Both C-EP and are monovalently connected to two oxygen atoms.
(a) A GO nanoribbon model with zigzag edges. The part between two dashed lines is a unit cell along the ribbon direction. (b) A GO structure model based on epoxy line defect.
Schematic experimental XPS curve and our first principles assignment.
R-CCS of carbon orbital for various oxidation species reported in experiment and calculated with atomic and plane wave basis sets in this work. The binding energy of C-E (287.2 eV) is set as a common reference point. The numbers in parentheses are the line widths of experimental peaks.
Article metrics loading...
Full text loading...